PUBLICATION

Characterization of the first knock-out aldh7a1 zebrafish model for pyridoxine-dependent epilepsy using CRISPR-Cas9 technology

Authors
Zabinyakov, N., Bullivant, G., Cao, F., Fernandez Ojeda, M., Jia, Z.P., Wen, X.Y., Dowling, J.J., Salomons, G.S., Mercimek-Andrews, S.
ID
ZDB-PUB-171021-2
Date
2017
Source
PLoS One   12: e0186645 (Journal)
Registered Authors
Andrews, Saadet, Dowling, Jim, Wen, Xiao-Yan, Zabinyakov, Nick
Keywords
none
MeSH Terms
  • Action Potentials
  • Aldehyde Dehydrogenase/genetics*
  • Animals
  • Behavior, Animal
  • Clustered Regularly Interspaced Short Palindromic Repeats*
  • Electroencephalography
  • Epilepsy/chemically induced*
  • Epilepsy/genetics
  • Epilepsy/physiopathology
  • Gene Knockdown Techniques
  • Pyridoxine/toxicity*
  • Zebrafish/embryology
  • Zebrafish/genetics*
PubMed
29053735 Full text @ PLoS One
Abstract
Pyridoxine dependent epilepsy (PDE) is caused by likely pathogenic variants in ALDH7A1 (PDE-ALDH7A1) and inherited autosomal recessively. Neurotoxic alpha-amino adipic semialdehyde (alpha-AASA), piperideine 6-carboxylate and pipecolic acid accumulate in body fluids. Neonatal or infantile onset seizures refractory to anti-epileptic medications are clinical features. Treatment with pyridoxine, arginine and lysine-restricted diet does not normalize neurodevelopmental outcome or accumulation of neurotoxic metabolites. There is no animal model for high throughput drug screening. For this reason, we developed and characterized the first knock-out aldh7a1 zebrafish model using CRISPR-Cas9 technology. Zebrafish aldh7a1 mutants were generated by using a vector free method of CRISPR-Cas9 mutagenesis. Genotype analysis of aldh7a1 knock-out zebrafish was performed by high resolution melt analysis, direct sequencing and QIAxcel system. Electroencephalogram was performed. Alpha-AASA, piperideine 6-carboxylate and pipecolic acid, were measured by liquid chromatography-tandem mass spectrometry. Our knock-out aldh7a1 zebrafish has homozygous 5 base pair (bp) mutation in ALDH7A1. Knock-out aldh7a1 embryos have spontaneous rapid increase in locomotion and a rapid circling swim behavior earliest 8-day post fertilization (dpf). Electroencephalogram revealed large amplitude spike discharges compared to wild type. Knock-out aldh7a1 embryos have elevated alpha-AASA, piperideine 6-carboxylate and pipecolic acid compared to wild type embryos at 3 dpf. Knock-out aldh7a1 embryos showed no aldh7a1 protein by western blot compared to wild type. Our knock-out aldh7a1 zebrafish is a well characterized model for large-scale drug screening using behavioral and biochemical features and accurately recapitulates the human PDE-ALDH7A1 disease.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping